Posted by gerry

Since the primary use-case for the Red Pitaya is a piece of instrumentation, it makes sense that the input impedance is high, to prevent loading the circuit under test. However if it is desired to use it as an SDR, this migh present some small issues as the standard impedance for radio transceivers is 50 ohms. The input impedance of the Red Pitaya is 1 Megohm which is a fair way away from where we need it to be.


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Posted by gerry

A while ago, while browsing Ham Radio channels on Youtube, I came across an interesting project. Chris, M0NKA, an obviously talented hardware designer had designed a QRP Software Defined Radio (SDR) based on the STM32F407 from STMicroelectronics.


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Posted by gerry

Among other great features of the Raspberry Pi is the General Purpose Input Output array (GPIO). This is an array of pins that can be programmed to behave as pretty much any I/O type that can be represented digitally. The pins can be switched on or off to represent binary 1s and 0s and controlled so as to emulate any communication protocol that uses bits (I2C, SPI, RS232 etc. etc.). However, as a first attempt at working with GPIO, I took a recommendation from Steve EI5DD and wrote a program that will key a transceiver and generate morse code.


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Posted by gerry

I recently upgraded my shack to an ICOM IC7300, which in the EU specification includes the 4 meter / 70MHz band. I do not have a vertical for 4m, or space for one right now, but had read about others using a small matching unit to provide the necessary match using the Diamond V2000, or Watson W2000, as my version is badged.

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Posted by gerry

At the Mayo Amateur Radio Rally a couple of years ago, a NI ham, Tom Herbison, MI0IOU was selling an interesting kit for the Raspberry Pi. It combined an Analogue Devices Clock Generator (AD9850) and an RF power meter (AD8307) to give a programmable sweep generator & detector... commonly known as a Wobbulator. I bought one and had an enjoyable afternoon not long afterward building it. It was a relatively easy build, and I got some use out of it tuning some Band Pass Filters I had built for use on multi-station portable ops.




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Posted by gerry

I have been playing with Software Defined Radio for a number of years, but recently advances in high-speed sampling has put relatively high quality, extremely high frequency SDR within reach of everyone. A few years ago Eric Fry reverse-engineered the communications from a Digital TV USB Dongle to see that it transmitted raw samples.

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Posted by gerry

Now that the weather is improving, I decided to dust off the /P kit and ensure that all was working will in anticipation of getting some outdoor operation. I had bought a lightweight dual-band beam for this purpose so decided to put it on a pole and see how it performed.

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Posted by gerry

The hugely hackable Girltech Im-Me has been used for many interesting hacks. However the internal antenna leaves a lot to be desired, being basically a little piece of wire.

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Posted by gerry

The FT817 from Yaesu is still the most featured portable radio available. The Elecraft KX3 might have better HF performance, but for sheer spectrum coverage, it doesn't come close... unless you spend a few hundred more Euros for the 2W output 2m or 4m transverter. You will definitely have a world class radio, but it still won't do UHF, and would cost something between twice and three times what an FT817 would.

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Posted by gerry

I have had an ASUS N56VZ laptop for about 18 months, and rate it as one of the best laptops I have ever had. I was dual-booting Windows 8 and Ubuntu off the 750GB hard drive since I got the laptop until one day I basically destroyed the Ubuntu install while playing with Docker.io

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